The present invention relates to a method of manufacturing rubber plates or sheets, particularly but not exclusively suitable for obtaining soles of footwear, and to plates, or parts thereof, thus manufactured.
In the present description, the term xe2x80x98rubber platexe2x80x99 is meant to indicate a flat product whether obtained from a moulding press piece by piece or in the form of a continuous sheet.
Coated rubber plates are currently manufactured and sold as flooring and/or facings and also as soles for footwear in general.
In order to be attractive to the public and for other commercial reasons, such plates have to be decorated and/or bear brand names or logos or be otherwise embellished. In the particular case of soles for footwear it is imperative to be able to impress some information, in the form of letters and numbers, on the sole, such as the shoe number, the trademark or the manufacturer""s name or other distinguishing signs.
No doubt a well executed decoration may notably increase the value to the public of a sole and thus also the footwear to which it is applied. Thus, it is a matter of great importance to be able to produce rubber plates or soles that are either decorated or can be decorated at will.
Traditionally, the operation of decorating and branding a plate or sole or marking the shoe number is carried out by a bass-relief formed during moulding of the sheet or plate (given that hot branding cannot be satisfactorily performed on rubber) or with special inks or transfer films.
The soles obtained from rubber plates are subsequently subjected to various kinds of finishing operations including die-cutting, sewing, gluing, grinding, grooving and the like. In the case of plates having a xe2x80x98velvetxe2x80x99-like coated surface, working on the plates or parts thereof, e.g. on soles obtained by die-cutting a rubber plate, is rather critical as the velvet surfaces are liable to become permanently dirty due to many possible causes, e.g. the presence of dust, oil, grease, trimming of the coating applied to the edges, contact with the operator""s hands etc., and more importantly it is then no longer possible to properly clean them with the result that the soles are effectively and irretrievably ruined.
Thus, it has already been suggested to cover the velvet surface of rubber plates with a protective film of plastics material that have to be decorated after having undergone a die-cutting operation.
Such a protective film shields the sheets from dirt and possible damage but prevents the plate itself or the soles obtained from it from being decorated.
Recourse is sometimes taken to the expedient of creating windows at the plate or sole areas to be decorated but of course such an operation involves additional costs and does not in any case provide protection from dirt or possible damage in the exposed areas where the protective film has been removed.
The main object of the present invention is to provide a method that makes it possible to easily decorate or brand rubber plates or soles provided with a protective film or covering layer without risking their surfaces getting dirty or in any other way deteriorating.
Another object of the present invention is that of removing or substantially reducing any of the above described drawbacks by providing a method of manufacturing of coated rubber plates particularly suitable for the soles of footwear that makes it possible to easily impress information in the form of numbers and letters as well decorative features, trademarks or the like on the plate surface.
Not the least important object of the present invention is that of providing a new and effective method of manufacturing rubber plates or soles that involves low additional production costs, thereby being competitive even from the economical viewpoint.
These and other objects are, chleved by a moulding method of manufacturing a rubber plate, or part thereof, particularly suitable for footwear soles, according to the present Invention, comprising the following operational steps:
coating at least on of said face of said rubber plate with at least one coating material including at least one heat and pressure color toning component,
applying onto each said coated face a film of transparent material that withstands heat and pressure required for causing each said color toning component to color tune, and
applying at least one heat and pressure impression means onto said film protective material, thereby causing permanent toning of the or each toning component and formation of predetermined images in said coating material.
Advantageously, the said coating material is a velvet paint.